The present invention relates to coupling adapters for use in the cooling and filtering of fluids, and, in particular, to a coupling adapter for coupling a fluid filter and a remotely-located fluid circulation device to the fluid reservoir of a hydraulic system.
Coupling adapters for coupling fluid filters and fluid circulation devices, such as heat exchangers or oil coolers, to a hydraulic system are well known in the art. These units find wide use in a variety of types of vehicles and engines for filtering and cooling transmission fluid and lubricating oil.
One such device, disclosed in U.S. Pat. No. 2,068,395 and referred to therein as a base casting, includes an upper flat, trapezoidal flange member and a lower grooved, circular flange member formed as by casting. A horizontally-extending bore passes through the base casting for receiving a stud bolt for securing the casting to the block of an engine. A heat exchanger is mounted atop the base casting upon the upper flat trapezoidal flange member. A cylindrically-shaped fluid filter element is secured to the lower grooved, circular flange member. Lubricating oil to be cooled and filtered passes from the engine into one side of the base casting where it is deflected upward into the heat exchanger. After passing through the heat exchanger, the oil returns back into the base casting. The cooled lubricating oil then passes through the base casting into the inner peripheral, cylindrical surface of the fluid filter where it is filtered. Filtered oil passes upward through the center of the fluid filter into the horizontally-extending bore of the base casting. From the horizontally-extending bore, the filtered oil is routed through a different section of the base casting to an outlet bore and then back into the engine. The base casting is provided with a pair of spring-loaded ball relief valves, one for by-passing the oil flow around the heat exchanger and the other for by-passing the oil flow around the fluid filter in the event the resistance of the flow through either the heat exchanger or the fluid filter becomes too great.
Another type of adapter for fluid cooling and filtering is disclosed in U.S. Pat. No. 3,463,317 and is referred to therein as adapter D. This adapter is designed for attachment to the fluid casing of a hydraulic system in place of a spin-on type fluid filter. The adapter is provided with an upper flat surface for abutment adjacent the outlet surface of the fluid casing. A central bore extends through the adapter for receiving a hollow, threaded nipple. The lower surface of the adapter includes a crescent-shaped recess partially surrounding the central bore. Two closely-spaced ports extend laterally from the side of the adapter for hose connection to a remotely-located fluid cooling element. One port extends through an L-shaped bend within the adapter to an opening through the upper flat surface to receive the fluid from the circular well of the fluid casing of the hydraulic system. The other port extends into the crescent-shaped recess within the lower surface of the adapter. A spin-on fluid filter attached to the lower end of the threaded nipple secures the filter to the lower surface of the adapter. Fluid to be cooled and filtered passes from the circular well of the fluid casing through the L-shaped port of the adapter to the remotely-located cooler element. The cooled fluid flows from the cooler element back to the other port of the adapter and into the crescent-shaped recess. The fluid then flows from the recess into the inner peripheral surface of the filter. Filtered fluid passes up through the center of the filter and through the hollow nipple back into the hydraulic system.
An additional type of adapter, similar in part to that of U.S. Pat. No. 3,463,317 employs a disk-shaped body having generally flat upper and lower surfaces. The upper surface includes a D-shaped recess or cavity. The lower surface includes a D-shaped recess separated from the D-shaped recess in the upper surface. A central bore extends through the disk-shaped adapter for receiving a hollow, threaded nipple. Two closely-spaced parallel ports pass through the side wall of the adapter, one extending into the upper D-shaped recess and the other into the lower D-shaped recess. A spin-on filter may be secured to the lower surface of the adapter by threaded attachment to the lower end of the hollow nipple. The upper threaded end of the nipple attaches the adapter with the spin-on filter to the fluid casing or reservoir of the hydraulic system. One version of this type of coupling adapter includes a ball and spring valve internally located within the adapter and situated between the two D-shaped recesses at a position diametrically disposed from the two ports.
The above briefly-described adapters possess a number of disadvantages and limitations which the present invention is intended to overcome. Foremost among these limitations is the number of turns or bends the fluid must undergo while passing through the adapter on its way to the cooling and filtering elements and the number of restricted areas, through which, and barriers, around which, the fluid must pass before re-entering the hydraulic system. These prior art adapters are seriously limited as to the types and sizes of fluid reservoirs to which they may be attached, as well as to the types and sizes of fluid filters with which they may be used. Additionally, these prior art adapters are limited in the manner in which they may be installed and coupled to fluid-cooling devices as a result of their design and geometric configuration. Finally, these prior art adapters do not provide, nor do they lend themselves to, the inclusion of a temperature-responsive valve system for by-passing the cooling path when the temperature of the fluid is relatively low.
Accordingly, a principal object of the present invention is to provide an improved coupling adapter having an increased and unrestricted flow of fluid through its internal passageways.
Another object is to provide a coupling adapter for coupling a variety of different types and sizes of fluid filters and remote fluid circulation devices to the fluid reservoir of a hydraulic system.
Still another object is to provide a coupling adapter for inter-coupling between a fluid reservoir of one size and a fluid filter of a size larger than that which the fluid reservoir was designed to receive.
An additional object is to provide a coupling adapter having increased spacing between ports for achieving unobstructed fluid flow into and out of the adapter and enabling a variety of types of fittings to be employed in coupling the adapter to a remotely-located fluid circulation device.
Yet another object is to provide a coupling adapter having an improved pressure-responsive valve for controlling the flow of fluid within the adpater.
A further object is to provide a coupling adapter having a thermally-responsive valve for regulating the flow of fluid according to its temperature.
Another object is to provide a universal coupling adapter that is useable with different sizes of fluid reservoir housings.